Adjustment and control of DAC end points e.g. zero scale, full scale or gain and offset is desirable in a number of circumstances. One of the more important uses is end point error correction. That is correction of zero scale and full scale errors and gain and offset errors.
Digital to analog converter (DAC) transfer function end point errors e.g. zero scale and full scale errors; offset and gain errors have historically been a problem effecting (DAC) accuracy. Previous attempts to reduce such errors have included laser trimming which applied to resistors only and required special hardware and wafer fabrication techniques and added significantly to the cost. Mixed signal (analog/digital) calibration is another approach but its results can be risky, performance is limiting and less dependable. It too increases expense. One common approach is to design for the optimal nominal desired result. But the higher the accuracy desired the greater the expense: more precision design and production required, added software and/or circuitry and more expensive fabrication techniques. In addition, compensating for such errors in systems including the DACs, and their preceding reference path plus subsequent analog chain of circuits (i.e. analog signal chain) requires even greater complexity and expense either in additional and highly accurate integrated circuitry or calibrating system(s) procedures integrated into the system software.